Embodiments in accordance with the present invention relate to a magnetic head and magnetic disc drive, in particular to the reliability of the reproduction elements of a magnetic head against the stress from the outside.
A prior art method of inspecting the reproduction elements of a magnetic head is disclosed in patent document JP-A-2004-22024. This patent document describes a method of measuring the output characteristics of a magneto-resistive effect type head in the state of applying alternating magnetic field without using a magnetic disc, and further, of measuring noise, output waveform fluctuation, and waveform asymmetric fluctuation, in addition to output fluctuation. Measurement is performed with varying magnetic field and temperature to the magnetic head as disturbance. An inspecting method is performed by measuring a lability of the reproduction elements in a static state, wherein a magnetic head showing lability higher than tolerance can be selectively excluded.
In the inspecting method as disclosed in JP-A-2004-22024 and described above, of the stresses applied to the reproduction elements in a practical magnetic disc drive, only temperature is made an issue. In a practical magnetic disc drive, a magnetic head suffers mechanical stresses by striking against a magnetic disc surface and against dust, so problems arise such as the reduction of reproduction output of the magnetic head, and the reversal of output polarity. It is desirable to provide a magnetic head having resistance to these stresses.